As the disparity between number of potential liver transplant recipients and available cadaveric organs has widened, novel approaches have been developed to permit the successful transplantation of the largest possible number of patients with end-stage liver disease. The most promising of these stategies has involved the application of adult to adult living donor liver transplantation (LDLT). More than fifteen U.S. transplant centers have now utilized LDLT as a standard method for liver replacement. Despite the increasingly widespread application of this approach, considerable heterogeneity exists betweencenters regarding donor and recipient evaluation as well as the surgical techniques employed. Moreover, information is lacking regarding outcomes of this procedure for both donor and recipient, no data available to identify donors or recipients who may benefit most (or least) from this procedure, and no data todetermine whether using LDLT is a cost-effectivestrategy. In this setting, we propose to participate as a transplant center (TC) in the LDLT Clinical Research Consortium. In this role, we propose to participate in the development of a prospective comprehensive data base and information core that will permit the dissection of the factors which lead to favorable, or unfavorable, outcomes in LDLT as compared to standardcadaveric tranplantation. The exisiting UVA STRANDS database will permit retrospective collection of data from LDLT and cadaveric transplants performed over the last 5 years. In addition, the TC proposes to build on its institutional strengths to lead two clinical research protocols. The first protocol will develop a Cost Utility Decision Analysis using the Adult to Adult Living Donor Liver Transplantation Cohort. This research will yield a valid decision analysis model that can be used in a general patient population to better define subpopulations that would benefit from LDLT as opposed to cadaveric liver transplant. Costs and utilities to the health care system and the patients involved will be clarified for use in patient counseling, medical decision-making, and policy formulation. The second clinical research proposal will examine the outcomes of LDLT in patients infected with hepatitis C and compare these outcomes to cadaveric controls. Mechanisms that contribute to rapid allograft infection and injury will be examined including hepatocyte infection, rates of viral replication and kinetics of serum viral clearance.